In an effort to understand these glaring conflicts, The Bee spent seven months interviewing more than a hundred farmers, industry leaders, public officials, illegal immigrants, religious leaders, policy experts and activists. The goal was to explain how inconsistent laws, policies and attitudes have made illegal immigrants a central — yet hidden — part of the Valley's economy.

First, consider the scope of the issue.

One out of 11 workers in California is an illegal immigrant, with most coming from Mexico, according to the Pew Hispanic Center. And the central San Joaquin Valley's multibillion-dollar agriculture machine — the economic engine that drives our entire region — is fueled mostly by the labor of illegal workers, according to surveys and industry leaders.

We are more dependent on illegal immigrants than ever. In 1989, only 7% of U.S. farmworkers were illegal immigrants, a U.S. Labor Department survey found. Estimates today range from half to two-thirds.

Illegal immigrants aren't just in agriculture: They cook restaurant meals, lay tile and clean hotel rooms. Many work for minimum wage or less and live in apartments or crowded rental homes. But others are foremen and crew bosses, making up to $50,000 a year and paying off mortgages.

All of them, however, eventually hit a ceiling because of their legal status: The farmworker who learns he can't get a better-paying job at the packinghouse because the owner won't accept his fake documents; the mother of three who can't get a job as a U.S. Census worker because she needs a legitimate Social Security card; the high school graduate who can't go to college because illegal immigrants don't qualify for public financial aid.

Life for illegal immigrants, as one put it, is like living in a golden cage — a land full of opportunities just beyond their reach.

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Illegal immigrants and the businesses that depend on them play a big game: Workers pretend to be legal, and employers pretend to believe them.

Valley farmers say they want a legal work force, but only about 2% use a federal database that quickly checks an employee's legal status. And while California and federal politicians condemn illegal immigration, they won't pass laws requiring all employers to use the database.

Fake-document vendors run a thriving underground industry in the Valley that provides a steady supply of fabricated Social Security and green cards. These vendors are sometimes connected with farm-labor contractors and human smugglers who provide all the services an illegal immigrant needs to sneak across the border, obtain fake documents and get a job. Authorities have had little success cracking down on the vendors.

The federal agency charged with stopping the flow of illegal immigrants, under pressure from employers, has been reluctant to launch an all-out assault. Aggressive crackdowns have backfired. And while immigration authorities have recently increased the number of businesses audited, none in the central San Joaquin Valley have been fined in the last eight years, despite their well-known use of illegal workers.

Studies show that illegal immigrants — who usually pay less in taxes than they use in government services — are a burden on local governments because of their low incomes, not because they won't work. Also, they often compete directly for low-wage jobs with some American workers, although businesses and consumers benefit from the cheap labor.

Farmers say that without illegal immigrants, their businesses — and the Valley's economy — would collapse. But some experts say farmers could survive without illegal workers if they were willing to pay more or invest in new technologies.

America's restrictive immigration laws make it nearly impossible for low-skilled Mexicans to come here legally unless they have close relatives who are legal residents. Even then, in some cases they must wait at least 18 years. The government's guest-worker program is rarely used by local farmers, according to federal data.

While most California residents believe illegal immigrants hurt the state, and most approve of Arizona's strict immigration enforcement law, a majority also believes that illegal immigrants should be allowed to keep their jobs and apply for legal status.

Some experts predict that the system will always be broken because too many people don't want change — even if they say they do.

Farmers get cheap labor, illegal immigrants get jobs, consumers pay less for services. No one wants to make difficult reforms that would disrupt this balance.

Said Howard Rosenberg, an agriculture labor management specialist at the University of California at Berkeley: "This works for too many people."

This story is one in a Fresno Bee series on illegal immigration in California.